This application requests funding for the acquisition of a hybrid triple quadrupole/linear ion trap mass spectrometer (4000 Q TRAP;Applied Biosystems) interfaced to a liquid chromatography (LC) system. The new instrument will be housed in the Proteomics Core Facility at the Pennington Biomedical Research Center (PBRC). This instrument is a critical component to support NIH-funded projects of more than ten investigators studying obesity, diabetes and aging. These projects involve detection, identification, characterization and quantification of lipids, fatty acids, metabolites, peptides and protein post-translational modifications. This instrument will allow these investigators to use mass spectrometric (MS) techniques for biomolecular analysis that are currently not available at PBRC or at any neighboring institutions. The facility collaborates with other researchers at Louisiana State University (LSU) Agricultural Center, LSU-Health Sciences Center (HSC) in New Orleans, LSU-HSC in Shreveport, Tulane National Primate Research Center, and small private companies in the South Louisiana region. These investigators will also have access to the technologies offered by this instrument. Today, the analysis of proteins, peptides, lipids, carbohydrates and metabolites using LC-MS/MS methods is commonly performed to identify molecules of biomedical significance. Methods for quantification of these biomolecules in complex matrices such as blood plasma or tissue samples are required for further verification, validation and characterization. The combination of high specificity of the triple quadrupole and high sensitivity of linear ion trap makes 4000 Q TRAP ideal for these projects. The selectivity and limit of quantification achieved using selected and multiple reaction monitoring (SRM and MRM) scan functions are best among all mass analyzers. The 4000 Q TRAP also has MS3 analysis capability which allows for identification and detailed structural characterization of biomolecules in a single injection. Using information dependent acquisition, these scan modes can be used in a variety of combinations including some less conventional combinations such as MRM/Enhanced product ion and MRM/MS3 depending on the application and need for sensitivity, selectivity and/or quantification. This combination of scan modes cannot be achieved by any other instrument. The instrument will be operated and maintained by trained personnel. The Director of the Proteomics Core Facility will schedule daily operation and provide technical expertise to the users. An advisory committee will ensure access to the major users and other NIH-supported investigators and will be responsible for the long term management of the instrument. PUBLIC HEALTH RELEVANCE: The 4000 Q TRAP mass spectrometer will be utilized by the NIH-funded investigators to explore mechanisms leading to obesity, diabetes, and aging and to understand biological pathways controlling circadian clock and blood brain barrier. The unique analytical tools offered by this instrument will also be used to develop biomarkers and to devise therapy for each disease state.